Cleaned out my EGR and IAC yesterday. This morning, my pickup began to miss horribly. So in the spirit of not knowing what I'm doing I ordered an MSD coil pack and Ford Motor Racing plug wires thinking it wasn't sparking. Then after throwing enough F-bombs to flatten a small middle eastern country, I got to thinking and pulled it back apart. I looked in the EGR tube and there was still some chunks in it. So I cleaned it out all the way this time. Then I went down to the auto parts store and picked up some injector cleaner. Within 10 miles the engine was running normally.

 

Krunkmoin, tell us again about the EGR.
Where is it, what does it do? I have a thread
printed out somewhere, I think, but will you
go over it for us?

 

The EGR stands for exhaust gas recircultion. There is a tube that comes off of your exhaust manifold that goes up to a valve on the side of your intake. From that valve it goes into a tube in your intake that has two holes, one for the left and right bank. In this engine for some reason carbon has a tendency to build up and eventually plug those two holes causing an MIL light. For a picture of this see "Common cause of low flow EGR".

 

did you have remove the TB to clean the two ports, or were you able to just remove the EGR valve and clean out the buildup? I'm getting the same EGR insufficient flow code and looked at removing my TB last weekend. It looked like a real pain in the a$$ so i sprayed a whole can of TB cleaner into the TB. It didn't work. the CEL stayed off for about 30 miles but came right back on. I'm getting substantial pinging from the motor under load, so I need to get the buildup cleaned out pretty quick. thanks for the help. BTW - I have a 99 Expy with the 5.4L.

Nathan

 

The purpose of an EGR is basically what it stands for. Exhaust Gas Recirculation. The exhaust gas is recirculated through the engine to reduce emissions into the atmosphere before being sent out the tailpipes. This actually reduces performance and makes the engine nasty. On Toyota Tacomas (which I had 2 of before my F150), we remove those for performance gains and to help the engine stay cleaner. We would remove the EGR stuff and reroute the coolant line and use blockoff plates to cover the holes. Once the computer was reset, the engine would notice the difference. Within 50 miles or so, you could feel a little gain in low end power. The TB stays cooler since there is no hot water running through it which means the intake air is cooler. Plus the TB stays cleaner. You did have to remember to put a 10 ohm resistor in place of the plug in for the egr sensor so not to get a CE light. Worked like a charm and cost around $10. Great "free" mod to do. I dont know where it even is on the 5.4L though....

 

To clean it you have to remove both the TB and intake, as in the neck between the TB and the upper manifold. Not sure if that is the correct wording. But you will need to break some of the stuff up w/ a screwdriver or coat hanger to get it all out. It's really not that bad to get off. Takes about 1 hour to take off, clean, and get back on. Probably couldn't hurt to have a new gasket on had for where the egr connects to the intake.

 

thanks for the info. One other question. Did you have to seperate the TB from the neck? It looks like the TB and the neck can be removed in one piece.

 

Nick_2000... a 10 ohm resistor will keep the CEL off? what power rating resistor did you use? i'd like to keep my light off for an emissions inpection, although i suspect the problem is the valve is stuck open.. code P0402 is what I keep getting. Anybody have an idea on chances of it passing emissions with the EGR experiencing 'excessive flow'?

 

Hmm. Excessive flow and passing emissions? Good question, here's my thought process. The EGR system is designed to reduce the formation of nitrous oxide molecules which form somewhere in the range of 2500 - 2600 degrees fahrenheit. By introducing exhaust gas into the intake you reduce the cylinder head temperature and thus reduce the production of NOx.<br>So given that, there's a chance that it would pass if they test for NOx but there are other problems that may occur because of the excessive flow.<br>What I'm trying to remember is why the introduction of the exhaust gas will reduce the temperature and if I recall from my flying days, it has to do with the density of the air involved. The exhaust gas is less dense and therefore by introductin the exhaust gas you are making the mixture rich which will reduce the cylinder head temperature.<br>If someone can confirm this for me I would greatly appreciate it, otherwise I'll have to pull out my high performance flying books.

 

Yes it will. It will keep the computer from realizing that the EGR has been removed. I dunno the power rating because i had a guy send it to me with the block off plates. It's white with a red stripe. I also had the PO402 code after the removal, but it wound up being the gas cap not on correctly. I dont know anything about emissions because here in Alabama we dont have any such thing. But the EGR removal helps the engine stay cooler and cleaner. The exhaust does stink a bit but I've been told its all the gases that werent burnt off.

 

Nick_2000 - thanks for the info, I guess I'll try a plain old regular size (1/4 or 1/2 watt) resistor...

oddsix - good news is NOx is NOT tested in my area of PA, they just started with emissions in our county, but are testing for HC and CO

hopefully, the resistor alone will do the trick, I have a bigger problem that needs to be dealt with anyway, lower ball joints AND a front hub/bearing unit (it's an AWD model) - looks like this year's safety inspection is gonna cost some bucks

 

I got hit with the lower ball joints and an idler arm at last years inspection. Topped off with the new tires I bought, it really hurt the wallet :-(

 

Can anyone elaborate on how I might view such a picture?
Thanks!